Campylobacter contamination is one of the major causes of food-borne illness, and can lead to Campylobacteriosis. Campylobacter are also a major cause of diarrhoeal illness in humans and are generally regarded as the most common bacterial cause of gastroenteritis worldwide. In the United States, Campylobacter are estimated to affect two million people a year. Common routes of transmission are ingestion of contaminated food, water or milk, eating raw meat, person-to-person sexual contact, and fecal-oral. The infectious dose for Campylobacter may be as low as 400-500 bacteria as shown by human feeding studies, however, the infectious dose and the dose response are dependent upon the strains used, and the age and physical condition of the individuals. Symptoms appear 2-10 days after ingesting the bacteria and include fever, abdominal cramps, and mild to severe diarrhea, which may be bloody. Most infections are caused by C. jejuni, normally found in cattle, swine, and birds, where it is non-pathogenic, however, the illness may also be caused by C. coli (also found in cattle, swine, and birds) and C. lari (present in seabirds in particular). Some strains of C. jejuni produce a cholera-like enterotoxin, which is important in the watery diarrhea observed in infections. Most Campylobacter infections clear on their own or with the aid of antibiotics, however, long-term sequelae include reactive arthritis, Guillain-Barré syndrome and Miller Fisher Syndromes.
Studies have shown that Campylobacter can be isolated from a wide variety of sources, including chicken, cattle, pets, goats, sheep and pond water and river water. Milk, particularly unpasteurised (raw) milk, and poultry are the most common food items associated with Campylobacter infection. Campylobacter may also be isolated from red meat, but the frequency of contamination is generally much lower than poultry. Isolation of Campylobacter from food sources is difficult because the bacteria are usually present in very low numbers since they generally do not multiply in the foods they infect. Culture methods require an enrichment broth containing antibiotics, special antibiotic-containing plates, incubation at two different temperatures, and a microaerophilic atmosphere with an elevated concentration of carbon dioxide. Isolation can take several days to a week. Identification of Campylobacter using current USDA methods for detection can take 2-3 days. There is a need for a rapid, sensitive and accurate method to detect C. jejuni, C. lari, or C. coli so that the contaminating or infectious source can be accurately detected and eliminated. There is also a need for methods that allow rapid and accurate diagnosis of C. jejuni, C. lari, or C. coli infections in humans so that infected individuals may be treated promptly to limit morbidity and prevent further infections.